The term Load balancing refers in the prior art to dividing the amount of work that a server must undertake between two or more servers of the same kind, so that more work is accomplished, and consequently all the clients will be served better (either more rapidly, or in a higher availability ratio). Load balancing can be implemented by hardware means, software means, or a combination of them.
On the Internet, Web sites having large throughput, usually use load balancing in order to achieve better performance of their Web servers.
Several approaches have been presented in the prior art for balancing the load between Web servers corresponding to a domain. One approach is to route each request in turn to a different server corresponding to the same domain name in the round-robin fashion (an arrangement of choosing all elements in a group equally in some rational order).
Typically, there is an element called a Load-balancer to which requests for service are directed, and from the load-balancer they are redirected to one of the servers participating in the balancing layout.
Since load balancing require multiple servers, it is usually combined with failover (i.e. automatically switching to a redundant or to a standby server) and backup services. According to this approach, there are two computers participating in the failover scheme, but only one computer (the main computer) is active, while the other (backup computer) stands-by. Whenever the main computer fails, the backup computer takes control over the IP, and starts serving as the Web server. The difference is that the backup computer does not serve any requests while in its standby mode. In some operations, the servers are distributed over different geographic locations.
Load-balancing methods known in the art are “request-directed”; i.e., a request for service (in the service/client mode) is directed to one of a group of servers providing the same service. Moreover, such methods are based on duplicating the service provider.
It is an object of the present invention to provide a method and system for balancing the load on a computer resource between computers, rather than balancing the requests for services, as in the prior art.
Other objects and advantages of the invention will become apparent as the description proceeds.